The UN Security Council is holding secret ballots on Monday to choose a candidate to replace Ban Ki-moon who has to leave after serving two five-year terms as the United Nations Secretary General.
The 15-member Security Council will cast a ballot for each of the 10 candidates, with the choices being encourage, discourage or no opinion.
The candidate chosen unanimously by the Security Council will be recommended for appointment by the UN General Assembly as the new secretary general who starts work in January 2017.
Ban, who had been initially selected for the post by the Security Council in October 2006, steps down on December 31. He was the first Asian head of the organization in 35 years.
Based on the UN’s unofficial regional rotation scheme, many analysts believe there is a good chance that the next UN chief will hail from Eastern Europe, which has not produced a secretary-general as of yet.
However, current tensions between Russia and Western permanent members over the conflict in Ukraine could potentially lead to a deadlock over an Eastern European nominee. In that case, one of the remaining candidates from non-Eastern European regions will assume the job.   
The selection of the secretary-general is subject to the veto of any of the five permanent members of the Security Council including  China, Russia, Britain, the United States and France.
The nominees for the position include five women, namely UNESCO Director-General Irina Bokova of Bulgaria; former Croatian FM Vesna Pusic; Moldova's former FM Natalia Gherman; former New Zealand PM Helen Clark, who heads the UN Development Program; Argentinian FM Susana Malcorra and former UN climate chief Christiana Figueres of Costa Rica. 
There are also five male candidates. They are Montenegro FM Igor Luksic; former Slovenian president Danilo Turk; former UN High Commissioner for Refugees Antonio Guterres, who is also a former Portuguese prime minister; former Serbian FM Vuk Jeremic; former Macedonian FM Srgjan Kerim and Slovak FM Miroslav Lajcak.
This photo shows a view of the United Nations General Assembly. (AFP photo)
The UN's first official secretary-general was Trygve Lie from Norway who was appointed in February 1946 and stayed in the job until November 1952.
Lie was preceded by Gladwyn Jebb from the United Kingdom who served as the acting United Nations secretary-general from October 1945 to February 1946.
The second secretary-general  was Sweden's Dag Hammarskjold who stayed in office for eight years. He was followed by Asia's U Thant from Burma who served for 10 years after his appointment in 1961 as the third secretary-general. 
Kurt Waldheim from Austria took the office from 1972 to 1981. Javier Pérez de Cuéllar from Peru came after him, from 1982 to 1991. Egypt's Boutros Boutros-Ghali served from 1992 to 1996.
And, Kofi Annan from the African country of Ghana served from 1997 to 2006, before South Korea's Ban was appointed as the secretary-general of the world body.